20年来部分黑土耕层有机质和全氮含量的变化

黑土有机质含量的变化一直倍受社会关注。根据第二次全国土壤普查的采样记录,2001年在吉林省黑土区采集了27个土壤样品,分析测定了耕层土壤(深度与第二次土普数据相同)的有机质和全氮含量。与第二次土普查数据对比发现,过去20年间,吉林省黑土土壤有机质和全氮含量有增有减,但平均水平无明显变化。与已有的研究对比分析,高产玉米生产条件下的根系碳输入量可能抵消矿化损失的有机质量,使水土流失不严重区域的黑土土壤有机质水平维持平衡,有机质含量下降的土壤可能是水土流失的结果。而在水土流失不严重地区土壤有机质则可能增加。     

松嫩平原玉米带土壤有机质和全氮的时空变异特征

采用地统计学和GIS相结合的方法,研究了松嫩平原玉米带1980～2005年间土壤有机质和全氮的时空变异特征.结果表明:去除异常值后,土壤有机质和全氮均符合对数正态分布,两个时期土壤有机质的平均含量分别为2.14%和2.54%,土壤全氮的平均含量均为0.12%.通过变异函数分析,两个时期土壤有机质和全氮均符合高斯模型,1...     

黑土区土壤有机质和全氮含量遥感反演研究

以东北典型黑土区耕地为研究区,以Sentinel-2A（全球环境与安全监测计划的第二颗卫星,于2015年6月23日发射）影像作为数据源,构建光谱指数,分别采用多元逐步线性回归（Multiple Stepwise Linear Regression, MSLR）和随机森林（Random Forest, RF）算法建立土壤有机质（SOM）和土壤全氮（STN）预测模型,并采用十折交叉验证方法评估模型的性能。研究对比分析了不同气候、土壤类型和地形下土壤有机质和全氮的空间分布差异。研究表明：① 海伦示范区的SOM和STN含量最高,其年均温最低,高程最高,年降水量多,SOM含量升高,其年均温最低,年降水量多,STN含量升高;② 与基于多元逐步线性回归算法建立的SOM和STN预测模型相比,随机森林算法建立的SOM和STN预测模型,有着更高的精度和稳定性;③ 运用RF算法建立的SOM反演模型的R²为0.96,均方根误差为5.49 g/kg,STN反演模型的R²为0.95,均方根误差为0.27 g/kg; ④ 不同示范区统一建立SOM和STN预测模型,有助于提高预测精度,实现跨区域建模与制图。     

湿地土壤有机质和全氮含量分布特征对比研究——以向海与科尔沁自然保护区为例

研究了土壤有机质及全氮在霍林河中下游的科尔沁和向海两个自然保护区湿地表层土壤中的水平分布及其在土壤剖面中的垂直分布特征。结果表明，与科尔沁自然保护区相比，向海自然保护区的空间分异程度较高，其表层对有机质及全氮的持留作用较强，碳的固定速率比氮累积更慢一些；盐碱化程度较高，湿地植被净化效应较显著；pH值对有机质和全氮的影响也更为显著。     

扎龙湿地克钦湖表层沉积物中有机质、全氮和全磷含量分布特征

为了了解扎龙湿地克钦湖沉积物中营养物质的分布状况,在扎龙湿地克钦湖设置了21个采样点,于2016年7月9日,采集了0?5 cm深度的沉积物样品,测定了表层沉积物样品中有机质、全氮和全磷含量;利用克里金插值法,绘制表层沉积物有机质、全氮和全磷含量的空间分布图,并分析了其空间分布特征及影响因素.研究结果表明,克钦湖0～5 ...     

森林土壤碳、氮淋失过程及其形成机制研究进展

大气氮沉降对森林生态系统碳截存和损耗过程的影响已引起广泛关注, 但对沉降氮在森 林生态系统中的去向、增氮对土壤中碳/氮转化过程的影响以及土壤氮饱和前后土壤渗漏液中溶 解性有机碳(DOC) 和溶解性有机氮(DON) 动态等方面的研究还不够深入。本文论述了近年来国 内外在土壤氮饱和及土壤碳、氮淋溶领域的最新研究进展, 从系统论的角度阐述土壤氮饱和过程 及内涵; 通过论述DOC 和DON 含量及其结构组成变化来揭示其对增氮/氮沉降的内在响应机 理; 论述了增氮对土壤无机氮转化的影响以及生物和非生物因素对沉降氮固持的贡献。指出土壤 氮饱和为土壤中的有效氮随时间增加超过了土壤中生物和非生物的持留能力, 导致土壤氮的净 矿化、净硝化、NO₃^-流失以及土壤酸化等过程发生一系列非线性变化。初步认为土壤中DOC 和 DON 对增氮的不同响应归因于氮素饱和过程的三个不同阶段。对于特定的生态系统来说, 需要 清楚地认识土壤氮素矿化、硝化、反硝化和固持等过程, 才能明晰土壤氮素状态以及随时间的演 变。另外, 指出在上述三个研究领域中存在的问题, 并提出拟解决的途径以及未来的可能研究方 向, 以期对该领域的研究提供参考。     

影响海岸带盐沼土壤有机质、TN和TP含量时空变化的关键因子：潮水和植被

为了更好地理解在潮水和植被交互作用梯度上有机质、全氮和全磷分布的特殊性,分别于生长季和非生长季在苏北盐沼沿近潮沟带和远潮沟带2条样线布设9个固定采样区,采集土壤样品,测定土壤有机质、全氮和全磷的含量。结果表明：植被和潮水的交互作用是决定土壤有机质、全氮和全磷时空变化的关键因素。相对于潮水,植被的影响更为稳定和持久;盐沼土壤有机质和全氮含量具有显著的空间和月份变化,空间变化主要包括植被带（潮水）梯度上和样带间（潮流）的差异,在植被带（潮水）梯度上植被带高于光滩,而植被带间呈现由海向陆的递减趋势,即互花米草(Spartina alterniflora)>盐地碱蓬(Suaeda salsa)>獐茅(Aeluropus littoralis)>芦苇( Phragmites australis);有机质样带间差异表现为在低位盐沼远潮沟带大于近潮沟带,而中位盐沼却是近潮沟带大于远潮沟带,全磷含量时间和空间变化上均不具显著性;pH、土壤含水量和盐分含量等与潮水作用直接相关的因子与距海距离呈负相关关系,土壤有机质、全氮和全磷与距海距离也表现为负相关关系,而土壤有机质、全氮和全磷含量与pH、土壤含水量及盐分含量等因子为正相关关系,一定程度上诠释了潮水对土壤有机质、全氮和全磷含量变化的影响。     

云龙湖沉积物碱性磷酸酶活力特征及其对氮、磷元素的作用

碱性磷酸酶能催化有机磷分解释放正磷酸盐,对湖泊治理研究具有生态学意义。以徐州市云龙湖为研究区,于2008年9月4日在云龙湖东、西两个区域共布设20个采样点,测定了沉积物的碱性磷酸酶活力,研究沉积物中碱性磷酸酶的分布及其活力与营养盐（总氮和总磷）的关系。结果表明,云龙湖东、西区沉积物的碱性磷酸酶活力的最大值都出现在沉积物表层（0～3cm层）,最小值都出现在底层（7～11cm层）;云龙湖东区上覆水中总氮和总磷含量高于西区;云龙湖东区沉积物中总磷和总氮含量的最大值都出现在底层,而西区则都出现在表层;东、西区沉积物中层（4～6cm层）的碱性磷酸酶活力都与其总磷含量显著正相关（东区：r=0＋776,n=10,P〈0．01;西区：r=0．642,n=10,P〈0．05）,研究区沉积物中层是碱性磷酸酶的活跃层;东区沉积物底层的碱性磷酸酶活力与其总氮含量显著正相关（r=0．838,n=10,P〈0．01）;东、西区沉积物表层的碱性磷酸酶活力与其总磷和总氮含量不相关。     

罗北凹地富钾卤水中锂、硼的空间分布和富集规律研究

文章基于自组织神经网络（SOM）和Kmeans耦合（SOM-KM）方法,利用罗北凹地65组富钾卤水水化学数据,对富钾卤水中锂（Li）和硼（B）资源空间分布和富集规律进行了系统性研究。研究发现富钾卤水中Li,B含量表现出一定的垂向分异性,自上而下B浓度增高,Li浓度降低。聚类结果表明,罗北凹地富钾卤水可聚为4类,各类地下水中Li、B浓度具有明显的空间差异性,高浓度的Li、B集中分布在罗北凹地中东部区域。此外,水化学特征离子分析结果表明,罗北凹地富钾卤水中Li、B元素富集主要受到蒸发浓缩及盐岩溶滤作用控制。     

The enrichments of organic matter and total nitrogen in sediment as affected by relavant factors

Serious soil erosion has already resulted in degradation of the Loess Plateau of China. Soil erosion is commonly accompanied by extensive soil nutrient loss. Because of enrichment processes, sediment nutrient content is often higher than that of natural soil. The objective of this study is to determine the enrichments of organic matter and total nitrogen in sediment in hilly and gully loess areas on the Loess Plateau of China. Measurements of enrichment ratios (ER) of organic matter (EROM) and total nitrogen (ERTN) in sediment as affected by rainfall, slope gradient, tillage, and fertilization were made in the field under natural rainfall conditions. The results showed that the enrichment of clay in sediment resulted in the enrichment of organic matter (OM) and total nitrogen (TN) in sediment. The averages of sediment clay ER, EROM and ERTN for the various slope gradients were 1.77, 2.09 and 1.61, respectively. The soil erosive module was negatively correlated with EROM and ERTN. Our results indicate that measures to reduce soil erosion, i.e. reducing rainfall erosivity, decreasing soil slope gradient, decreasing fertilizer use, and using level trenches, may increase EROM and ERTN. Both quantity and quality of sediment yield should be considered when implementing erosion control measures.     

The enrichments of organic matter and total nitrogen in sediment as affected by relavant factors

1IntroductionResearch results have shown that overland flow firstly removes fine particles of topsoil because the fine soil particles can be easily transported in runoff (Burwell etal., 1975; Alberts etal., 1983; Gregory 1991). The component differences of fine soil particles between the sediment resulting from soil erosion and the original soil were studied (Meyer etal., 1975; Loch etal., 1982; Cogo, 1983). Sediment was normally composed of soil aggregates and particles of different diamet…     

黑河流域土地利用变化对土壤有机碳和全氮储量的影响——元分析（英文）

Land use and cover change(LUCC) is an important indicator of the human-earth system under climate/environmental change,which also serves as a key impact factor of carbon balance,and a major source/sink of soil carbon cycles.The Heihe River Basin(HRB) is known as a typical ecologically fragile area in the arid/semi-arid regions of northwestern China,which makes it more sensitive to the LUCC.However,its sensitivity varies in a broad range of controlling factors,such as soil layers,LUCCs and calculation methods(e.g.the fixed depth method,FD,and the equivalent mass method,ESM).In this study,we performed a meta-analysis to assess the response of soil organic carbon(SOC) and total nitrogen(TN) storage to the LUCC as well as method bias based on 383 sets of SOC data and 148 sets of TN data from the HRB.We first evaluated the calculation methods and found that based on the FD method,the LUCC caused SOC and TN storage to decrease by 17.39% and 14.27%,respectively;while the losses estimated using the ESM method were 19.31% and 18.52%,respectively.The deviations between two methods were mainly due to the fact that the FD method ignores the heterogeneity of soil bulk density(BD),which may underestimate the results subsequently.We then analyzed the response of SOC and TN storage to various types of the LUCC.In particular,when woodland and grassland were converted into cultivated land or other land types,SOC and TN suffered from heavy losses,while other LUCCs had minor influences.Finally,we showed that increasing the depth of the soil layers would reduce the losses of SOC and TN storage.In summary,we identified a series of controlling factors(e.g.soil layer,the LUCC and calculation method) to evaluate the impact of the LUCC on SOC and TN storage in the HRB,which should be considered in future research.     

内蒙古河套永济灌域渠道底泥有机质和总氮含量特征

排灌系统底泥特征是反映土地利用变化生态影响的重要途径,为此对内蒙古河套灌区永济灌域灌排系统底泥有机碳和总氮含量进行了系统研究。结果表明:灌域内永济给水干渠(简称永济干渠)与四号、五号排水干沟(简称四排干、五排干)表层底泥的有机质(OM)及总氮(TN)含量特征分布有所差异。其中均以五排干上游底泥中含量最高,OM与TN平均值分别为3.60%和0.35%,超出河套地区平均值的4.82倍和2.94倍;其底泥有机指数也达到重污染水平,富营养化程度较高;永济干渠底泥OM与TN含量最低,分别为1.41%和0.03%,属于清洁贫营养化级别;四排干底泥OM与TN含量介于五排干和永济干渠之间,其上游较为清洁,基本接近平均值,C/N平均在17左右。排干底泥有机质与总氮含量之间显著相关,y_(TN)=0.141x_(OM)-0.180(r=0.978;P<0.001)。     

The impact of land use and cover change on soil organic carbon and total nitrogen storage in the Heihe River Basin: A meta-analysis

Journal of Geographical Sciences - Land use and cover change (LUCC) is an important indicator of the human-earth system under climate/environmental change, which also serves as a key impact factor...     

新疆石河子草滩湖湿地沉积物地球化学特征及其古环境分析

以新疆石河子草滩湖湿地作为研究地点,采用化学分析手段,获取该地区4 000 a B.P.以来有机质和总氮TN等数据,并结合孢粉数据,综合探讨古气候变化特征。在500-1 080 a B.P.和2 190-3 800 a B.P.期间,有机质和TN含量较高,此时气候较为湿润,泥炭累积;而在1 080-2 190 a B.P.期间,有机质和TN含量均处于剖面最低值,可能出现一次干旱事件,不利于泥炭堆积。湿地开垦为农田,其有机质和TN含量变化迅速减少,养分大量损失,可见开垦活动是引起湿地退化的原因之一。     

Total N,total P and organic matters content in floodplain soils of Xianghai Nature Reserve

Soil sediment samples of 10 layers with a spacing of 10 cm each were collected in different floodplain zones adjacent to Huolin River in the Xianghai Nature Reserve, and contents of total N, total P and organic matters were analyzed. The results showed that contents of total N, total P and organic matters were generally decreasing with the increase of distance from sample locations to the river channel, and contents of the three items were generally higher in the upper soil layer than that in the lower soil layer. The content variations displayed how flooding functions influenced nutrient matter content variations in floodplain soils since the flood inundation frequencies of the sample locations varied. The correlation analysis displayed that there were remarkable relativities between total N, total P and organic matters within definite spatial distance from the Huolin River channel.     

Total N, total P and organic matters content in floodplain soils of Xianghai Nature Reserve

Soil sediment samples of 10 layers with a spacing of 10 cm each were collected in different floodplain zones adjacent to Huolin River in the Xianghai Nature Reserve, and contents of total N, total P and organic matters were analyzed. The results showed that contents of total N, total P and organic matters were generally decreasing with the increase of distance from sample locations to the river channel, and contents of the three items were generally higher in the upper soil layer than that in the lower soil layer. The content variations displayed how flooding functions influenced nutrient matter content variations in floodplain soils since the flood inundation frequencies of the sample locations varied. The correlation analysis displayed that there were remarkable relativities between total N, total P and organic matters within definite spatial distance from the Huolin River channel.     

长江口潮滩有机质稳定碳同位素时空分布与来源分析

通过测定长江口潮滩悬浮颗粒有机质和表层沉积有机质在枯水季节 (2006年2月 )和洪水季节 (2006年8月 )的稳定碳同位素值,对有机质潜在来源及局部岸段改造作用进行了分析。结果显示,悬浮颗粒有机质稳定碳同位素值在2月明显低于8月,变化范围分别在-25.8‰~-23.4‰和-25.1‰~-22.9‰,主要是受径流量枯洪季变化和浮游生物生长季节变化两种因素的叠加作用。表层沉积有机质2月和8月的稳定碳同位素分别为-25.0‰~-20.4‰和-24.7‰~-19.5‰,季节变化不明显,主要来自悬浮颗粒物的沉降。除受大背景环境因素影响,局部环境对潮滩有机质也有一定的改造作用,污水、支流河水的输入对悬浮颗粒有机质碳同位素有一定的影响,埋藏的潮滩植物和底栖微藻则对沉积有机质有部分贡献。